The invention relates generally to well servicing apparatus and more particularly for running well hardware such as a pump assembly or the like, by cable, into a well and pulling such hardware from the well.
Typical oil well pulling and running equipment, for example, includes an elongated suspension boom or mast from which cable is run into the well and associated sheaves, winching equipment, etc. for driving the cable. The mast must have a height above a platform or other surface upon which it is mounted at a well head sufficient to suspend the well hardware for servicing, assembly and the like, and the mast must further have sufficient strength to withstand the forces encountered in pulling the hardware from a well. Oil well pumping assemblies can, for example, have a height approaching 50 feet, and the forces involved in pulling such assemblies from a well can reach as high as 250,000 to 300,000 pounds.
To meet the requirement of adequate strength to withstand pulling forces in a mast of sufficient length to accommodate the well hardware, typical masts and their associated supports have therefore been of extremely heavy and robust construction. Such structures are costly to manufacture and, due to their weight, energy-inefficient to transport, erect, and dismantle. This invention seeks to provide an alternative approach to the problem of combining in a well pull-and-run suspension structure, the facility for accommodating relatively tall well hardware assemblies with the capability of withstanding the forces encountered in pulling such hardware from a well.